Freight is regularly transported by air, sea, land and rail. In each case, the freight is loaded into a cargo vessel, such as the trailer of a truck or a railway freight car. Unfortunately, due to limitations in the support or decking assemblies within the cargo vessels, the full area of the vessel is not utilized. In particular, the top half or so of the vessel is typically referred to as dead space because it is often left empty due to the impracticalities of loading that dead space with cargo.
Since freight transportation companies are often paid by weight or volume, it is thus highly desirable to find a way to maximize the use of the space within the cargo vessel, in particular, to use the dead space.
Cargo is often supported within the vessel on a decking or shelving system and therefore, it is desirable to have a decking or shelving system which is vertically adjustable to support cargo in the vertical dead spaces and which system can also accommodate various levels of decking or shelving. However, it is crucial that the system be securely locked in any one vertical position yet at the same time be easily manouevred to another vertical position, either to accommodate different load configurations or for stowage when not in use.
While multi-level decking systems are known and currently employed in the freight transportation industry, the applicant is not aware of any systems which maximize the full cargo space of the vessel by allowing use of the vertical dead space, which are easily adjustable in height and width, yet which securely lock the cross members in place to prevent unwanted vertical movement of the cross members. Indeed, the applicant is aware of a current problem in the industry, particularly in the trucking industry, in which decking systems that are vertically positioned at different levels by means of pins mating with apertures in tracks are prone to become dislodged by virtue of the normal motion and jostling of the cargo vessel or by virtue of upwards force exerted on the cross-member.
By way of example of cargo support systems which have been designed in the past but which fail to adequately address the design concerns of the industry, the applicant is aware of the following references: Canadian Patent 464,167 of Evans Products Company, issued Apr. 4, 1950; Canadian Patent 683,264 also of Evans Products Company, issued Mar. 31, 1964; U.S. Pat. No. 3,534,692 of Val Verde, issued Oct. 20, 1970; U.S. Pat. No. 4,079,677, of Vandergriff et al., issued Mar. 21, 1978; and U.S. Pat. No. 4,091,745, of Patch, issued May 30, 1978. The applicant is also aware of U.S. Pat. No. 5,338,137, of Jensen, issued Aug. 16, 1994, which describes an adjustable decking system in which a spring activated latching member is engaged within an opening in a vertically oriented track to secure a beam assembly in place. However, the latching member of the Jensen reference is designed to be easily moved from one vertical position to another. Therefore, the latching member is prone to be easily dislodged from its vertical position by a person exerting an upward force of the beam assembly, or by the simple movement of the cargo vessel, caused for example by the truck passing over potholes or the like in roads, with the result that the cargo will fall from its support.